1. Field of the Invention
The present invention relates to a system and a method used to determine whether a floatation volume of a capsule medical apparatus that is floating in liquid is adequate.
2. Description of the Related Art
Capsule medical apparatuses that have image-taking and wireless-communication functions are commonly used in the field of endoscopy. A capsule medical apparatus is inserted into a subject, such as a patient, from the mouth in order to observe the interior of the internal organs of the subject. The capsule medical apparatus in the subject sequentially takes in-vivo images of the internal organs (hereinafter, sometimes referred to as “in-vivo images”) at predetermined intervals while moving through the internal organs by peristalsis. The capsule medical apparatus sequentially transmits the in-vivo images to the outside. The capsule medical apparatus repeatedly takes and wirelessly transmits in-vivo images over a period of time until it is excreted by the subject.
A group of in-vivo images that are taken by the capsule medical apparatus is received by a receiving device outside the subject and stored in a portable recording medium in the receiving device. The portable recording medium that stores therein the in-vivo images of the subject is detached from the receiving device and then attached to an image display device. The image display device loads the group of in-vivo images from the portable recording medium and displays each of the loaded images on its display. A health professional, such as a doctor or a nurse, observes the interior of the internal organs of the subject by observing each in-vivo image that is displayed on the image display device. Based on the observation result, the health professional can diagnose the subject.
Such capsule medical apparatuses include a capsule medical apparatus whose specific gravity relative to a liquid, such as water, is set lower than 1, and that sequentially takes in-vivo images of a subject while floating in the liquid that is introduced into the internal organs of a subject (see Japanese Patent Application Laid-open No. 2007-175448).
When the floatation volume of a capsule medical apparatus in liquid (i.e., the amount of protrusion of the capsule medical apparatus above the level of the liquid to the atmosphere) changes, the state where in-vivo images are taken by the capsule medical apparatus that is floating also changes depending on the change in the floatation volume in the liquid. In this case, the state where the interior of the subject is observed by observing in-vivo images may be altered unintentionally. Therefore, it is desirable that the floatation volume of the capsule medical apparatus in the liquid be in a predetermined range to ensure a stable state where in-vivo images are taken (i.e., the state where the interior of the subject is observed).